ASC students assist at mammoth dig

(10-03-2011)

The Denver Museum of Nature & Science received help recently from 21 Adams State earth sciences students of Dr. Jared Beeton. Dr. Beeton is a research associate with the museum and the lead geologist for a dig site on BLM land in the northern San Luis Valley where mammoth bones were uncovered in March. Curator of Archaeology Steven R. Holen is overseeing the dig for the museum.

They don't call it a "dig" for nothing. After the top 40 feet of soil are removed with a bulldozer, students go to work with shovels, trowels, bamboo tools, and brushes.

"The site has a complicated geologic setting that serves as an excellent outdoor classroom," Beeton said. "There are geological, paleontological, and possibly anthropological stories here."

Madeline Brinkley, Kayla Lanoue, and Alex Grothus conserve soil removed near a 26,000-year-old mammoth rib bone they unearthed. A senior geology and physical geography major and Porter Scholar, Lanoue considered the find a highlight of her 23rd birthday.

The bones were buried beneath 40 feet of alluvial fan sediments and are estimated by radiocarbon dating at about 26,000 years old.

Dr. Jared Beeton and Brianna Boyd take soil samples.

"It's pretty cool to say you found a mammoth bone in the San Luis Valley," said physical geography major Brianna Boyd, as she displayed a two-inch piece of mammoth ivory she had just excavated. With a minor in anthropology, Boyd also worked on the site over the summer, as an intern with the BLM.

Digging, sifting, and meticulously screening soil and gravel, the Adams State group unearthed three rib bones Sept. 27, as well as numerous bone and tusk fragments. To date, the site has yielded part of a mammoth skull, a two-foot tusk, three teeth, and three thoracic vertebrae, as well as teeth from prehistoric camels. Also uncovered were bones of rodents, which are "important little critters," Holen said. "They tell us what the environment was like."

Back on campus, Beeton's students are analyzing soil samples from the site. Their tests can determine moisture content, texture, and the percentage of organic carbon, which conveys information about vegetation and climate at the time the bones were deposited.

Steve Holen (right), of the Denver Museum of Science and Nature, examines rock and bone revealed as Kyle Bufis sifts through dirt.